Typewriting machine



Se t. 19, 1933. w. F. HELMOND TYPEWRITING MACHINE Filed July 16, 1929 2 Sheets-Sheet l //7 venfar p 1933- w. F. HELMOND 1,927,169

TYPEWRITING MACHINE Filed July 16, 1929 2 Sheets-Sheet B //7 van for: %m 9% 1], Af%y.

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Patented Sept. 19, 1933 UNITED STATES PATENT OFFICE TYPEWRITING MACHINE William F. Helmond, West Hartford, Conn., as-

signor t0 Underwood Elliott Fisher Company, New York, N. Y., a corporation of Delaware Application July 16, 1929. Serial No. 378,656

19 Claims. (01. 19'773) stopped for every type-impression, at a rate running as high as a thousand impressions per minute. Hence the carriage must be very light. This entails weakness, and it is found therefore difficult to secure the requisite stiffness, especially at the pivotal joints of the main members of the carriage, on account of the necessity that the parts must work freely. To shift the platenframe up and down for printing capital letters, it is mounted upon shift-arms which guide and drive it. Owing to the weakness of the platenframe, it has been found practically difficult to make proper connection between it and the shiftarms. One of the features of the present invention is to overcome this difficulty by springing the piaten-frarne into place between the shift-arms, so that the parts are permanently under compression, to insure a rigid pressure joint. By separating the platen-frame from the shiftarms by rows of ballbearings at the ends of the platen-frame, with hardened washers to take the thrust of these balls, rigidity of the platenframe endwise of the main carriage is assured, which is a necessity in order to secure accurate spacing between the typed impressions upon the work-sheet, while the platen-frame shifts up and down with great freedom, notwithstanding the rigidity of the platen-frame with the car against an abutment that is arranged upon the type-bar segment. In order'to remove the shiftarms. and shaft from the main carriage, it was necessary to drive out a pin or two by which one of the arms is fastened to the shaft, thereby releasing the arm from the shaft, so that the arm could be pulled off from the end of the shaft, thereby making it possible for the shaft to be pulled out-from the other bearing on the car- In order to replace the parts, it was necessary to replace the fastening pin in the hole,

and the hole was often found to be too large, and the pin was punched so as to expand it in the hole, and often this operation spoiled the pin. Moreover, the bearing of the shaft in the cocentric-collar was nickel-plated and unsatisfactory, for no looseness can be permitted in the mounting of the carriage upon the typewriter.

An object of the invention is to overcome these difiiculties, which is done by discarding the escentric-collars from the main carriage, and substituting upon the ends of the carriage a pair of gudgeons which are inserted into the hubs of the platen-shifting arms, concentrically with their rock-shaft. The bail, consisting of said arms and said rock-shaft, according to the present improvement, 'may be supported by said gudgeons. The latter are mounted in bosses that are cast upon the ends of the main carriage at its rear, and said bail nests down between said bosses, and can be lifted intact from the main carriage, it only being necessary to with draw the gudgeons. Each gudgeon projects from an eccentric, the head of which is provided with a screw-driver nick for rotation. Either end of the platen may be adjusted a little forward or backward, as required. Each boss is split, and the split portions are connected bya binding screw, so-as to hold the eccentric where adjusted. In removing the bail, it is not necessary to take it apart; simply loosen its eccentric and pull a gudgeon out from the bail, and then loosen the counterbalancing spring from the carriage; whereupon the bail can be taken out. Replacing is equally simple. form a manufacturing unit.

Another of the objects of the invention is to relieve the shock and reduce the noise of operation of the up and down shifting platen-frame. To this end, the front and back stops at the ends of the platen-frame have a yielding construction, but accuracy is not sacrificed. The platen-frame rests on these yielding stops, two in front and two in rear. When the platen-frame is shifted up, it is arrested by said front yielding stops.

It is a feature that the front yielding stopblocks serve to arrest theplaten-frame in both its up strokes and its down strokes, and are adjustable to bring the platen to its true upper-case position, without altering the normal or lowercase position of the platen. Each stop-block is mounted in a downwardly and rearwardly inclined position, and the front seating portions or rests on the platen-frame are inclined to" match. Eachstop-block is adjustable in a direction parallel with its inclination, but it has The bail with the spring can frame, carriage and carriage and the weak platen-frame thereon from such shocks. To this end, about a thirtysecond of an inch clearance is provided at the front between the bottom edge of the platen frame-end and the top surface of each end bar of the carriage. If the platen-frame is sprung down by a blow or shock, it can yield only a thirty-second of an inch, whereupon the platenframe-end contacts with the top of the carriage end, and no further yield is possible, so that injury is avoided, especially to the lightly con structed adjustable stop-blocks.

In its rear the platen-frame is provided with end rests or feet, in the form of level springy plates, which may be integral with brackets that are secured to the back of the platen-frame.

. These rests set down upon fiat blocks or surfaces that are formed upon the tops of the aforesaid bosses on the main carriage-frame that carry the adjustable eccentrics of the platen-shift unit. These springy rests or plates minimize shock and the noise, but are sufficiently stiff to cooperate with the front solid stops to prevent undue depression of the somewhat yieldable platen-frame under a blow or other shock.

The difiiculty is also experienced, especially with Underwood typewriting machines having long carriages, that there occurs considerable downward vibration, especially at the left-hand end of the carriage. This occurs during operation, and impairs the alignment of the type-impressions on the work-sheet. This is especially noticeable when the platen is in its elevated p0- sition for writing capital letters. The platenframe teeters down at its left-hand end and appears to vibrate rythmically, and the extent of vi bration tends to increase.

A feature of the invention is the provision of means for breaking up the rythin of vibration,

and especially for preventing the platen-frame.

from teetering down in the manner stated.

551 There is provided for this purpose a vibrationdarnper which is in the form of a small yieldable bumper that extends down from the platen frame to a point about two-thousandths of an inch above the platen-shift-rail. This vibrationdainper offers no friction to impede the progress of the carriage, but it is efficient in arresting the vibration, which is due inpart to thefact that nearly the entire mass of the main carriageframe and platenis above the point at which the carriage is arrested by means of its rack and escapement pinion. 1

Other features and advantages will hereinafter appear. I s

In the accompanying drawings,

Figure 1 is a sectional plan of a tight but freev joint between the platen-frame and one of'the arms by which it is supported.

ure 2 is a perspective view of the platenappurtenances, some parts being broken away.

Figure 3 is a sectional side elevation of the carriage and associated parts.

Figure 4 is a sectional plan showing eccentric mounting of the shift-bail upon the typewritercarriage.

Figure 5 is a sectional front view of the carriage and other portions of the machine.

Figure 6 is a plan of the shift-bail, a portion whereof is seen at Figure 4.

The cylindrical platen 10 is carried upon an axle 11, which is journaled in the ends 12-13 of a platen-frame, these ends being vertical plates,

which at their front lower ends are joined by a tie-rod 14, and at their rear ends have inwardlybent flanges or tongues 15, which are fastened by screws 16 to the ends of a tie-bar 17.

Ihis platen-frame is borne upon a. carriage having end bars 18, front bar 19 and rear bar 20.

Therear bar has supporting lugs 21, which slide upon a fixed guide-rail 22; and the front bar has a roll 23 which runs upon a rail 24. The movements of the carriage are controlled by a rack 25, meshing with a pinion 26 connected to an escapement-wheel 2'7, with which cooperate carriage-feeding dogs 23, the carriage being driven by a spring-barrel 29. Type-bars 30 are mounted in a segment 31 to strike against the front of theplaten.

The platen is shifted up and down by means of a shift-rail 32, which is carried upon a frame 33, having a rcck-shaft 34 and operated by a keyactuated lever 35. A roll 36 supports the platen frame upon said shift-rail 32, said roll being pivoted in a bracket 37 which extends down from the tie-rod 14; said bracket having a hook 38 to catch under the shift-rail. 1

The platen-frame is shifted up and down by means of a parallel-motion linkage, including a pair of upper lift arms 39 and a pair of lower links 40, the lift arms being pivoted at 41 to the main carriage, the links being pivoted at 42 to the end bars 18 of the carriage, and the platen-' frame itself forming the connecting member of the linkage.

For convenience in assembling and disassembling the platen-frame upon the carriage, the shift arms 39 are provided with open bearings or hooks 43 adapted for the reception of gudgeons' or studs 44 that project oppositely from the exteriors of the platen-frame-ends 13. Each stud has a seat 45 which is'held against the outer face of the'frame 13 by riveting the stud at 46 over the inner edge of the stud-hole 4? in the plate. Upon the outer end of the stud is placed a loose collar 48, held in place by the head of a screw 49. This collar may fit tightly in the hook 4.3 of the shift-frame, but is freely revoluble upon the stud to facilitate motion between the platenframe and the lift-frame.

It is important to prevent endwise play or shake of the platen-frame in the lift arms 39, the latter being rigidly mounted uponla rockshaft 50, which is journaled upon the main car riage and provided with a counterbalancing' To make the platen-frame fit very,

spring 51. tightly between the lift arms 39, and at the same time permit free movement of the joint between the arms and the platen-frame, there is provided for each end of the platen-frame a row of antifriction balls 52, which are carried in a brass 001- I lar or spacer 53, and operate between a hardened washer or flange 54 provided upon the collar 48 and a hardened washer55 that is mounted upon the gudegon 44. The end plates 12, 13 of the platen-frame are of springy sheet metal, and said the upward throw of the platen-frame. A binding by drawing or punching it from sheet metal to frame is made a little over-length, so that it has to be sprung into place between the lift arms 39, and tends to spring said arms apart, so that the parts are constantly under tension, and the platen-frame is very tightly held by the arms. The balls 52, however, permit very free play in the joint, so that the shifting motion of the platen can be effected with a requisite ease and rapidity.

The lift arms are provided with hubs 56 fixed by pins 5'7 upon the ends of the transverse horizontal rock-shaft 50, the arms and rock-shaft forming a bail which can be assembled (Figure 6) and placed in the machine as a unit. In the ends of the shaft are formed sockets 59, in which are inserted gudgeons 60 that project inwardly from eccentrics 61, which are journaled in bosses 62, forming parts of horns which are cast upon the extreme ends of the main platen-frame at the rear, and project upwardly and laterally from the carriage, as seen at Figure 2. These two bosses are therefore separated by the entire length of the carriage, and thus it is convenient to nest the Figure 6 bail-unit down in between the bosses; the bail-arms overlying the carriage-ends, and the platen-frame nesting between the arms. The eccentrics are inserted in the bearings 63 provided in said ears 62, and, by means of nicks 64, the same are rotated independently of each other to adjust the platen forwardly or backwardly at either end. Then binding screws 65 are tightened to draw together the separated portions of each boss 62,.which is split at 66. The counterbalancing spring 51 is secured at one end to a bracket 67, which is fasi tened by screws 68 to the rear bar 20 of the main carriage, from which they are removed when it is desired to take out the shift-bail unit. Said unit may be completed with said spring and the arms 39 upon inserting the unit in the machine. The gudgeons are hardened, and the ends of the rock-shaft may also be hardened and wear is thus avoided, avoiding the previous troubles with nickel-plated eccentric-bearings.

In its normal lower-case position the platenframe rests at its corners upon front and rear stops. The front stops 69 are blocks which incline downwardly and rearwardly, and the platenframe has rests or foot-portions '70 with inclinations to match. The stop-block is an open one- -piece frame, which has an under side '71 which is parallel with 69 and slides in a diagonal slot 72 cut in a boss '73, one boss formed upon each end of the carriage. At its rear end the adjustable stop-block 69 is formed on the under side with a horizontal stop-surface'M. A level stop-shoulder '75 is formed upon the front of each of the platenframe-ends 12 and 13. Each front stop-block may be adjustable independently of the other, to raise and lower the stop-face '74, to increase or diminish screw '76 is threaded into the slotted block 73 for catching upon the stop-block and clamping it where adjusted. This stop-block is made of springy metal, and may be made in one piece form an oblong cup. Then the bottom is punched out of the cup, leaving only thespringy sides which are shown in the drawings. There is sufficient yield in these stop-blocks to reduce substantially the shock of arresting the descending platen-frame, and to quiet the operation.

The yielding of these stop-blocks, however, is limited by means of a stop or foot 79, which is formed on each platen-frame-endand normally stands a thirty-second of an-inchabove the top surface 78 of the end bar 18 of the main carriage. This'limits the extent of the downward yield of the weak platen-frame to a thirty-second of an inch, so that if'undue force is accidentally applied upon the platen frame, the latter is firmly arrested by the contact of the stop '79 with'the solid rest 78.

Owing to the parallel relation of the inclined stop 69 with its opposite side 71, the stop may be adjusted in parallelism, so that the normal lower position of the platen-frame is not varied, but remains constant for the adjustment up and down of the stop-surface 74. Thus the length of the stroke may be regulated, while the platen retains its original normal-level in the machine.

At the rear the platen-frame has stop-plates or rests 80 projecting outwardly from its ends, and normally resting upon fiat surfaces or blocks 81 formed upon the bosses 62 which carry the eccentrics 61. These plates 80 are in the form of fiat level shoulders which project from brackets 82, which have angle plates 83 whereby they are attached by screws 16 to the back of the tie-bar 17 which forms part of the platen-frame; a'rod 84 being secured by screws 85 in said brackets, to support and guide a side-edge guide-86 for the work-sheet, Figure 3. Each plate or step 80 is joined to its bracket 82 by means of a neck-portion 87, which permits bending of the plate 80 up and down, to secure the proper vertical adjust" ment with relation to the rest 81. While the plate 80 and the bracket 82 may bend or spring, still they are sufficiently stiff to afford proper support for the platen-frame in conjunction with the front feet 79, so as to guardagainst liability of buckling of the light platen-frameunder-accidental rough usage.

The tie-rod 14 that connects the ends of the platen-frame is provided with eye-blocks 88, in which fit a stiffening rod 89. To the left-hand block 88 is secured, by means of a screw 90, Figure 3, a bumper in the shapeof a vertical foot or plate 91, which is bent to form a horizontal loop-shaped bumper 92 that occupies a position about two thousandths of an inch above the shiftrail 32. The top of this bumper or damper is bent over the top of the block 88 at 93, and has an open slot that fits a dowel-pin 94 provided in the top of theblock. The bumper is made in loop form to afford opportunity. for adjustment of the device up and down, and also to provide a yield in case it is subjected to undue pressure accidentally. This support 92 is placed at the left-hand end of the platen, and is effective throughout the main part of its travel. When the bumper or vibration-dampener travels beyond the shift-rail 32, the types will strike upon the part of the platen that is not subject to the downward teetering action above mentioned.

At all parts of the line of typing, the platen runs smoothly, and the type-impressions show perfect alignment even while the machine is running at high speed.

Variations may be resorted to within the scope frame andthe bail-arms, said arms provided I;

with open bearings to permit removal of said platen-frame, the latter having exterior gudgeons dropped into said bearings, collars fitting loosely on said gudgeons and fitting tightly in said open bearings, and ball spacers in the form of collars upon said gudgeons, each collar having a hardened flange forming one bearing for its circle of balls, and a hardened Washer forming the opposite bearing.

2. In a typewriting machine, the combination with a main letter-feeding carriage having ends, of a platen-frame, a shift-bail unit to the forward end of which the platen-frame is journaled, bosses forming portions of horns projecting laterally from the ends of said carriage, said shiftbail unit nested between said bosses and overlying said carriage-ends, said platen-frame filling the space between said carriage-ends and nested within said bail, and gudgeons projecting towards each other from said bosses, said bail being hinged upon said gudgeons for detachment as a unit.

3. In a typewriting machine having tracks, the combination with a main carriage thereon, said carriage having ends, of a platen-frame upon said carriage, a shift-bail unit to the forward end of which the platen-frame is journaled, horns jutting laterally from the ends of the carriage and rising above said carriage-ends, said shiftbail unit extending the length of the carriage and nested between said horns, the shift-bail arms overlying said carriage-ends, gudgeons projecting towards each other from said horns, said bail being detachably hinged as a unit upon said gudgeons, and eccentrics mounted in said horns, said gudgeons being formed upon said eccentrics, said eccentrics being independently adjustable to true the platen relatively to said tracks.

4. In a typewriting machine, the combination with a main letter-feeding carriage, having ends of a platen-frame thereon, a shift-bail forming a unit and having arms to the forward ends of which the platen-frame is journaled, said platenframe filling the space between said carriageends, bosses forming portions of horns extending laterally from the ends of said carriage, said shift-unit extending the length of the carriage and nested between said bosses, and gudgeons projecting towards each other from said bosses,

the shift-arms having sockets in which said gudgeons fit, the gudgeons being movable to permit detachment of the shift-bail as a unit from the carriage.

5. In a typewriting machine, the combination with a letter-feeding carriage, a platenframe and a shift-bail mounted on the carriage to shift the platen up and down, of a set of yielding front and back stops upon which the platen" frame rests, the front stops serving also to yieldingly arrest the upward shift of the platen-frame.

6. In a typewriting machine, the combination with a letter-feeding carriage, a platen-frame and a shift-bail mounted on the carriage to shift the platen up and down, of a set of yielding front and back stops upon which the platen-frame rests, the front stops serving also to yieldingly arrest the upward shift of the platen-frame, said front stops being adjustable to vary the extent of the stroke of the platen-frame while preserving the normal or 1ower-case position of the platen-frame.

and back stops upon which the platen-frame rests, the front stops serving also to yieldingly arrest the upward shift of the platen-frame, said front stops being adjustableto vary the extent of the stroke of the platen-fra1ne while preserving the normal or lower-case position of the platen-frame, each of said front stops being in the form of a block, and means whereby said block, is mounted in an inclined position for adjustment in oblique direction, each stop having a level stop-face on its under side to arrest the upward shifting of the platen-frame, whereby the adjustment of the stops obliquely may vary the extent of the up and down shift of the platenframe; the platen-frame having oblique rests normally supported upon said oblique stops, and parallel with the direction of the adjustment of said stops, so that adjustment of the stop-block does not vary the normal position of the platenframe.

8. In a typewriting machine, the combination with a letter-feeding carriage, a platen-frame and a shift-bail mounted on the carriage to shift the platen up and down, of a set of yielding front and back stops upon which the platen-frame rests, said platen-frame being yieldingly supported upon said front and back stops, and having a minute clearance above the carriage, to permit the platen-frame to yield downwardly until it comes in solid contact with the carriage, where by it is then firmly supported.

9. In a typewriting machine, the combination with a letter-feeding carriage, a platen-frame and a shift-bail mounted on the carriage to shift the platen up and down, of a set of yielding front and back stops upon which the platenframe rests, the front stops serving also to yieldingly arrest the upward shift of the platen-frame, said front stops being adjustable to vary the extent of the stroke of the platen-frame while preserving the normal or lower-case position of the platen-frame, said stops having the form of blocks inclined downwardly and rearwardly, and the platen-frame having rests or foot-portions with inclinations to match the stop-blocks.

10. In a typewriting machine, the combination with a letter-feeding carriage, a platen-frame and a shift-bail mounted on the carriage to shift the platen up and down, of a set of yielding front and back stops upon which the platenframe rests, the front stops serving also to yieldingly arrest the upward shift of the platen-frame, each of said stops being in the form of an open one-piece frame or block having parallel sides, and bosses in the carriage having diagonal slots, one side of each stop-block being inserted in the corresponding diagonal 'slot for adjustment in oblique direction.

11. In a typewriting machine, the combination with a letter-feeding carriage, a platen-frame and a shift-bail mounted on the carriage to shift the platen up and down, of a set of yielding front and back stops upon which the platen-frame rests, the front stops serving also to yieldingly arrest the upward shift of the platen-frame, each of said stops being in the form of an open onepiece frame or block having parallel sides, and bosses in the carriage having diagonal slots, one side of each stop-block being inserted in the corresponding diagonal slot for adjustment in oblique direction, and means for clamping each block where adjusted, each block having a level under side or shoulder to arrest the upward'shift of the platen-frame.

V 12. In a typewriting machine, the combination with a letter-feeding carriage, a platen-frame and a shift-rail mounted on the carriage to shift the platen up and down, of a set of yielding front and back stops upon which the platenframe rests, the front stops serving also to yieldingly arrest the upward shift of the platen-frame, each of said stops being in the form of an open one-piece frame or block having parallel sides, and bosses in the carriage having diagonal slots, one side of each stop-block being inserted in the corresponding diagonal slot for adjustment in oblique direction, said stop-block made of springy metal and drawn in one piece to form a cup, the bottom of which is removed.

13. In a typewriting machine, the combination with a letter-feeding carriage, a platen-frame and a shift-bail mounted on the carriage to shift the platen up and down, of a set of yielding front and back stops upon which the platen-frame rests, the front stops serving also to yieldingly arrest the upward shift of the platen-frame, each of said stops being in the form of an open onepiece frame or block having parallel sides, bosses in the carriage having diagonal slots, one side of each stop-block being inserted in the corresponding diagonal slot for adjustment in oblique direction, and means for clamping each block where adjusted, each block having a level under side or shoulder to arrest the upward shift of the platen-frame, said stop-block made of springy metal and drawn in one piece to form a cup, the bottom of which is removed.

14. In a typewriting machine, the combination with a letter-feeding carriage and a platen-frame mounted thereon for up and down shifting, of stops for the platen-frame, in the form of yieldable plates projecting outwardly from the ends of the platen-frame, the carriage having laterally projecting seats upon which said stop-plates rest, and brackets whereby said plates are attached to said platen-frame, each plate being integral with its bracket and joined thereto by means of a neck-portion which permits bending of the plate up or down for adjustment.

15. In a typewriting machine, the combination with a carriage, a platen-frame mounted to shift up and down upon the carriage, and a shiftrail upon which said platen-frame runs, of means to dampen the downward vibration of the platenframe during the rapid operation of the carriage, said dampening means in the form of a yieldable bumper that is mounted upon the platen-frame and extends down therefrom to a point within a minute distance of the rail, and in position to reach the rail when the platen-frame teeters down.

16. In a typewriting machine, the combination with a carriage, a platen-frame mounted to shift up and down upon the carriage, and a shift-rail upon which said platen-frame runs, of means to dampen the downward vibration of the platenframe during the rapid operation of the carriage, said dampening means in the form of a yieldable bumper that is mounted upon the platen-frame and extends down therefrom to a point within a minute distance of the rail, and in position to reach the rail when the platen-frame teeters down, said platen-frame having a roll to run upon said rail, and said vibration-dampener being mounted on the left-hand end of the platenframe. 7

17. In a typewriting machine,'the combination with a carriage, a platen-frame mounted to shift up and down upon the carriage, and a shift-rail upon which said platen-frame runs, of means to dampen the downward vibration of the platenframe during the rapid operation of the carriage, said dampening means in the form of a yieldable bumper that is mounted upon the platen-frame and extends down therefrom to a point within a minute distance of the rail, and in position to reach the rail when the platen-frame teeters down,-said bumper in the shape of a vertical foot which at its bottom is bent to form a horizontal loop to afford opportunity for adjustment up and down, and to provide a yield.

18. In a typewriting machine, the combination with fixed carriage-tracks, of a main letter-feeding carriage having ends, and running upon said tracks, a revoluble platen, a frame having ends in which said platen is journaled, said frame filling the space between the carriage-ends, a bailunit including forward-extending arms between which the platen-frame is confined and in which the platen-frame is detachably hinged, said carriage having at its ends rear laterally and upwardly protruding horns formed with bosses, said platen-frame nested between said bail-arms, and said arms overlying the ends of said carriage and nested between said bosses, and gudgeons mounted in and projecting towards each other from said bosses, said bail being detachably hinged as a unit upon said gudgeons and accessible for ready detachment asa unit.

19. In a typewriting machine, the combination with fixed carriage-tracks, of a main letter-feeding carriage having ends, andrunning upon said tracks, a revoluble platen, a frame having ends in which said platen is journaled, said frame filling the space between said carriage-ends, a bail including forwardly-extending arms between which the platen-frame is confined and in which the platen-frame is detachably hinged, said carriage having at its ends rear outwardly and upwardly protruding horns formed with bosses, said bail-arms overlying the ends of said carriage andnested between said bosses, and'gudgeons mounted in and projecting towards each other from said bosses, said gudgeons having eccentrics mounted in said bosses beyond the ends of the carriage for rotative adjustment, said eccentrics being adjustable independently of each other to true the platen relatively to said carriage-tracks.

WILLIAM F. HELMOND. 

